2.6.1.B18: archeosine synthase (ammonia)
This is an abbreviated version!
For detailed information about archeosine synthase (ammonia), go to the full flat file.
Reaction
Synonyms
amidinotransferase QueF-Like, ammonium:preQ0-tRNA aminotransferase, Pcal_0221, QueF-L, QueF-like
ECTree
Advanced search results
General Information
General Information on EC 2.6.1.B18 - archeosine synthase (ammonia)
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
evolution
metabolism
physiological function
additional information
despite distinct catalytic functions, phylogenetic distributions, and only 19% sequence identity, the two enzymes, QueF and QueF-L, share a common preQ0 binding pocket, and likely a common mechanism of thioimide formation. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. But like QueF, QueF-L possesses an active-site cysteine that serves as a catalytic nucleophile, reacting with the nitrile group to form a covalent thioimide intermediate. The enzymes belong to the tunneling-fold (T-fold) structural superfamily. QueF-L and QueF (from Bacillus subtilis, PDB ID 4F8B, and Vibrio cholerae, PDB ID 3UXJ) exhibit 18-20% sequence identity, structure comparison, detailed overview. The preQ0-binding pocket is defined by a cleft between two subunits from the same pentamer. QueF (EC 1.7.1.13) is unique to bacteria and the Q branch of the pathway and catalyzes the NADPH-dependent reduction of the nitrile group of preQ0 to the amine of preQ1
evolution
the organism lacks an archaeosine synthase, but comprises two proteins that inversely distribute with ArcS and each other. QueF-like (QueF-L), is a homologue of the bacterial enzyme QueF, which catalyzes the NADPH-dependent reduction of preQ0 to 7-aminomethyl-7-deazaguanine (preQ1) in the queuosine pathway
evolution
-
despite distinct catalytic functions, phylogenetic distributions, and only 19% sequence identity, the two enzymes, QueF and QueF-L, share a common preQ0 binding pocket, and likely a common mechanism of thioimide formation. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. But like QueF, QueF-L possesses an active-site cysteine that serves as a catalytic nucleophile, reacting with the nitrile group to form a covalent thioimide intermediate. The enzymes belong to the tunneling-fold (T-fold) structural superfamily. QueF-L and QueF (from Bacillus subtilis, PDB ID 4F8B, and Vibrio cholerae, PDB ID 3UXJ) exhibit 18-20% sequence identity, structure comparison, detailed overview. The preQ0-binding pocket is defined by a cleft between two subunits from the same pentamer. QueF (EC 1.7.1.13) is unique to bacteria and the Q branch of the pathway and catalyzes the NADPH-dependent reduction of the nitrile group of preQ0 to the amine of preQ1
-
evolution
-
the organism lacks an archaeosine synthase, but comprises two proteins that inversely distribute with ArcS and each other. QueF-like (QueF-L), is a homologue of the bacterial enzyme QueF, which catalyzes the NADPH-dependent reduction of preQ0 to 7-aminomethyl-7-deazaguanine (preQ1) in the queuosine pathway
-
evolution
-
despite distinct catalytic functions, phylogenetic distributions, and only 19% sequence identity, the two enzymes, QueF and QueF-L, share a common preQ0 binding pocket, and likely a common mechanism of thioimide formation. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. But like QueF, QueF-L possesses an active-site cysteine that serves as a catalytic nucleophile, reacting with the nitrile group to form a covalent thioimide intermediate. The enzymes belong to the tunneling-fold (T-fold) structural superfamily. QueF-L and QueF (from Bacillus subtilis, PDB ID 4F8B, and Vibrio cholerae, PDB ID 3UXJ) exhibit 18-20% sequence identity, structure comparison, detailed overview. The preQ0-binding pocket is defined by a cleft between two subunits from the same pentamer. QueF (EC 1.7.1.13) is unique to bacteria and the Q branch of the pathway and catalyzes the NADPH-dependent reduction of the nitrile group of preQ0 to the amine of preQ1
-
evolution
-
the organism lacks an archaeosine synthase, but comprises two proteins that inversely distribute with ArcS and each other. QueF-like (QueF-L), is a homologue of the bacterial enzyme QueF, which catalyzes the NADPH-dependent reduction of preQ0 to 7-aminomethyl-7-deazaguanine (preQ1) in the queuosine pathway
-
in the Euryarchaeota, the last step of the archaeosine biosynthetic pathway involves the amidation of a nitrile group on an archaeosine precursor to give formamidine, a reaction catalyzed by the enzyme archaeosine synthase (ArcS). Most Crenarchaeota lack ArcS, but possess two proteins that inversely distribute with ArcS and each other, and are implicated in G+ biosynthesis. One of these is the protein QueF-like (QueF-L) from Pyrobaculum calidifontis, which demonstrates the catalytic activity of QueF-L. Possible routes to G+-tRNA in Crenarchaeota possessing QueF-like (QueF-L) enzymes compared to the known pathway in Euryarchaeota that utilizes ArcS to carry out the amidation of preQ0-modified tRNA, overview
metabolism
the amidinotransferase QueF-Like (QueF-L), responsible for the final step in the biosynthesis of archaeosine in the D-loop of tRNA in a subset of Crenarchaeota. The archaeal homologue of QueF, QueF-Like (QueF-L), found in a subset of Crenarchaeota that lack ArcS, is capable of producing G+-modified tRNA
metabolism
-
the amidinotransferase QueF-Like (QueF-L), responsible for the final step in the biosynthesis of archaeosine in the D-loop of tRNA in a subset of Crenarchaeota. The archaeal homologue of QueF, QueF-Like (QueF-L), found in a subset of Crenarchaeota that lack ArcS, is capable of producing G+-modified tRNA
-
metabolism
-
in the Euryarchaeota, the last step of the archaeosine biosynthetic pathway involves the amidation of a nitrile group on an archaeosine precursor to give formamidine, a reaction catalyzed by the enzyme archaeosine synthase (ArcS). Most Crenarchaeota lack ArcS, but possess two proteins that inversely distribute with ArcS and each other, and are implicated in G+ biosynthesis. One of these is the protein QueF-like (QueF-L) from Pyrobaculum calidifontis, which demonstrates the catalytic activity of QueF-L. Possible routes to G+-tRNA in Crenarchaeota possessing QueF-like (QueF-L) enzymes compared to the known pathway in Euryarchaeota that utilizes ArcS to carry out the amidation of preQ0-modified tRNA, overview
-
metabolism
-
the amidinotransferase QueF-Like (QueF-L), responsible for the final step in the biosynthesis of archaeosine in the D-loop of tRNA in a subset of Crenarchaeota. The archaeal homologue of QueF, QueF-Like (QueF-L), found in a subset of Crenarchaeota that lack ArcS, is capable of producing G+-modified tRNA
-
metabolism
-
in the Euryarchaeota, the last step of the archaeosine biosynthetic pathway involves the amidation of a nitrile group on an archaeosine precursor to give formamidine, a reaction catalyzed by the enzyme archaeosine synthase (ArcS). Most Crenarchaeota lack ArcS, but possess two proteins that inversely distribute with ArcS and each other, and are implicated in G+ biosynthesis. One of these is the protein QueF-like (QueF-L) from Pyrobaculum calidifontis, which demonstrates the catalytic activity of QueF-L. Possible routes to G+-tRNA in Crenarchaeota possessing QueF-like (QueF-L) enzymes compared to the known pathway in Euryarchaeota that utilizes ArcS to carry out the amidation of preQ0-modified tRNA, overview
-
enzyme QueF-L functions as an amidinotransferase in the biosynthesis of G+-modified tRNA
physiological function
QueF-L catalyzes the conversion of the nitrile group of the 7-cyano-7-deazaguanine (preQ0) base of preQ0-modified tRNA to a formamidino group
physiological function
-
QueF-L catalyzes the conversion of the nitrile group of the 7-cyano-7-deazaguanine (preQ0) base of preQ0-modified tRNA to a formamidino group
-
physiological function
-
enzyme QueF-L functions as an amidinotransferase in the biosynthesis of G+-modified tRNA
-
physiological function
-
QueF-L catalyzes the conversion of the nitrile group of the 7-cyano-7-deazaguanine (preQ0) base of preQ0-modified tRNA to a formamidino group
-
physiological function
-
enzyme QueF-L functions as an amidinotransferase in the biosynthesis of G+-modified tRNA
-
in the presence of preQ0, the enzyme reveals a symmetric T-fold homodecamer of two head-to-head facing pentameric subunits, with 10 active sites at the inter-monomer interfaces. Bound preQ0 forms a stable covalent thioimide bond with a conserved active site cysteine similar to the intermediate previously observed in the nitrile reductase QueF. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. A large positively charged molecular surface and a docking model suggest simultaneous binding of multiple tRNA molecules and structure-specific recognition of the D-loop by a surface groove. Ligand docking study of wild-type and SeMet-labeled enzyme, overview
additional information
the conservation of Cys21 in QueF-L (Pyrobaculum calidifontis QueF-L numbering) and QueF (Cys55 inBacillus subtilis QueF numbering, PDB ID 4F8B), which in QueF participates in the catalytic mechanism via nucleophilic attack of the thiol group on the nitrile of preQ0 to form a covalent thioimide intermediate, suggests that QueF-L might utilize a similar intermediate in the mechanism to form the formamidine of G+
additional information
-
in the presence of preQ0, the enzyme reveals a symmetric T-fold homodecamer of two head-to-head facing pentameric subunits, with 10 active sites at the inter-monomer interfaces. Bound preQ0 forms a stable covalent thioimide bond with a conserved active site cysteine similar to the intermediate previously observed in the nitrile reductase QueF. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. A large positively charged molecular surface and a docking model suggest simultaneous binding of multiple tRNA molecules and structure-specific recognition of the D-loop by a surface groove. Ligand docking study of wild-type and SeMet-labeled enzyme, overview
-
additional information
-
the conservation of Cys21 in QueF-L (Pyrobaculum calidifontis QueF-L numbering) and QueF (Cys55 inBacillus subtilis QueF numbering, PDB ID 4F8B), which in QueF participates in the catalytic mechanism via nucleophilic attack of the thiol group on the nitrile of preQ0 to form a covalent thioimide intermediate, suggests that QueF-L might utilize a similar intermediate in the mechanism to form the formamidine of G+
-
additional information
-
in the presence of preQ0, the enzyme reveals a symmetric T-fold homodecamer of two head-to-head facing pentameric subunits, with 10 active sites at the inter-monomer interfaces. Bound preQ0 forms a stable covalent thioimide bond with a conserved active site cysteine similar to the intermediate previously observed in the nitrile reductase QueF. Due to tight twisting of its decamer, QueF-L lacks the NADPH binding site present in QueF. A large positively charged molecular surface and a docking model suggest simultaneous binding of multiple tRNA molecules and structure-specific recognition of the D-loop by a surface groove. Ligand docking study of wild-type and SeMet-labeled enzyme, overview
-
additional information
-
the conservation of Cys21 in QueF-L (Pyrobaculum calidifontis QueF-L numbering) and QueF (Cys55 inBacillus subtilis QueF numbering, PDB ID 4F8B), which in QueF participates in the catalytic mechanism via nucleophilic attack of the thiol group on the nitrile of preQ0 to form a covalent thioimide intermediate, suggests that QueF-L might utilize a similar intermediate in the mechanism to form the formamidine of G+
-